Author Topic: The Laser Project.  (Read 783041 times)

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Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #250 on: October 25, 2010, 07:29:47 AM »
Thanks Jeff, good call.  ;D

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #251 on: October 27, 2010, 05:40:29 AM »
Something lasers are pretty good at is ablating inks and dyes which is why they are often used for tattoo removals. They are also pretty good at removing the dye layer from anodized alluminium and here is an example.
It's only a scrap piece of material which I had kept to be used on another project but I thought I would give this a try and as it happens it turned out reasonably well, I think.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Overloaded

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Re: The Laser Project.
« Reply #252 on: October 27, 2010, 07:01:02 AM »
COOL Tweak !
What size is it ? Stepover ? Time to run ?
Thanks,
Russ

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #253 on: October 27, 2010, 07:16:32 AM »
Hi Russ,

Total time probably about 20 minutes, the image is just 90mm x 60mm and the vertical step size was 0.06mm.

As soon as I lay my hands on a decent gloss finish piece of black anodized I will try and make a better job of this, larger image and smaller step size perhaps.  ;)

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Sam

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Re: The Laser Project.
« Reply #254 on: October 27, 2010, 12:10:21 PM »
Neat stuff Tweakie. I had often wondered how your laser would work on anodizing. That could prove to be very useful with my own projects. I had thought about just simple vector patterns, but seeing the image you done, completely opened up new ideas. Thanks a bunch for posting your work!
"CONFIDENCE: it's the feeling you experience before you fully understand the situation."

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #255 on: October 29, 2010, 12:41:51 PM »
Thanks Sam.

I never seem to be able to take the best photographs of a lot of stuff so I had another crack at this one, this time without the flash.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline budman68

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Re: The Laser Project.
« Reply #256 on: October 29, 2010, 12:43:38 PM »
Nice!  ;)
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Offline ostie01

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Re: The Laser Project.
« Reply #257 on: October 29, 2010, 01:16:23 PM »
Is it your girlfriend  ::)

 ::)

Jeff

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #258 on: October 30, 2010, 04:41:52 AM »
Quote
Is it your girlfriend

In my dreams, along with 10 million other guys.  ;D ;D

A BIG problem
I have an issue with, what is commonly termed, ‘banding’. It can just be seen on this image but is perhaps better seen on this one http://www.cooperman.talktalk.net/files/27_files/image762.jpg .
This is not the same thing as encountered with some colour printers etc where there is insufficient colour depth for the image it is a distinct band of some 10 – 50 lines having a different contrast or brightness. I have run 5 identical images, one at a time, with the same settings, side by side, on the same material and the banding is different on each – it appears to be quite random in nature.
I have been doing a lot of reading and various forums searching to try and find an answer but it just seems to be a mystery.
Some have suggested that it is a mismatch between stepover and vertical pixel count, plausible but this should then produce a repeating pattern.
Different laser machine manufacturers disagree about the cause and almost all say their machines don’t exhibit banding but their competitors machines do.
Glass tube (DC excited) lasers seem to be more prone to this problem than RF excited lasers.
There is undoubtedly more than one type of ‘banding’ therefore there is obviously more than one cause and cure.

If any of you Guys have any suggestions for things I can try to eliminate this problem I would be more than grateful – I really must get to the bottom of this one.

Thanks,

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline budman68

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Re: The Laser Project.
« Reply #259 on: October 30, 2010, 07:15:08 AM »
I'm sure you've already come up with this, but can you raster at different angles to "cover" up the banding and smooth everything out? Or doesn't it work that way?

I know some CNC woodworking fellas do this to smooth everything over when using ballnose cutters and thought maybe this would be the same effect?

Dave
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